Look up project trail numbers with one detail request

A numeric project selector paged through GET /api/v1/trails?projectId=... sorted by update, up to 20 pages of 100. gh/entireio already has 2,099 trails, so its oldest were unreachable ("exceeded its page budget" after about 8.6s), and a trail updated mid-scan could be skipped. The detail route GET /{host}/{project}/trails/{trailId} documents trailId as a ULID or a project-local number (projectTrailDetail), so resolve the number with that one request, check the returned number and project, and use the ULID after.

The target now records the project number when resolution learns it, and an empty project comment list says "No discussions on trail #N" rather than the trail's ULID.

CLAUDE.md's findings rule names the cli/<n> form for project trails and the bare number otherwise.